E-mobility as a Mobile Energy Storage: The Potential of V2G in Power Grid Transformation

Vehicle-to-Grid (V2G) to technologia dwukierunkowego ładowania, która umożliwia przepływ energii z akumulatora pojazdu do sieci oraz w kierunku odwrotnym. Innymi słowy, elektryczne auta przestają być wyłącznie odbiorcami prądu – stają się także jego dostawcami, aktywnie wspierając system energetyczny. W dobie transformacji energetycznej i rozwoju odnawialnych źródeł energii (OZE) koncepcja wykorzystania e-mobility jako mobilnych magazynów energii nabiera szczególnego znaczenia.

What is V2G Technology?

Vehicle-to-Grid refers to the intelligent, two-way integration of electric vehicles with the power grid. In practice, it requires special charging stations and energy management systems that control when a vehicle should charge and when it should discharge energy back to the grid. Key components of the V2G ecosystem include: bidirectional charging infrastructure, software for grid communication, and real-time control protocols.

Thanks to this setup, an electric vehicle can absorb energy when there is a surplus in the system (e.g., at night or during sunny midday hours with high PV generation) and feed it back during peak demand periods. This flexibility benefits both EV owners and grid operators – creating a symbiotic relationship between electric transport and the power grid.

Global Trends and V2G Pilot Projects

V2G technology is currently being tested and piloted around the world, aligning with the broader trend of using energy storage to stabilize the grid and integrate renewables.

• United States: In California and other states, pilot projects are integrating electric school and fleet buses into the power grid. These vehicles often have large batteries (150–250 kWh) that remain unused for most of the day, making them ideal for discharging energy during peak hours. For example, in the suburbs of Boston, a fleet of school buses delivered a total of 3 MWh of energy back to the grid in 2021 – enough to power around 100 homes for a day. In Southern California, a utility launched a program in 2022 offering high compensation rates for each kilowatt-hour fed back into the grid from bus batteries – showing just how valuable vehicle participation can be for grid balancing.
• Japan: A V2G Pioneer. Japan has been a pioneer in V2G technology. Following the 2011 energy crisis (triggered by the Fukushima nuclear disaster), the CHAdeMO charging standard (CHArge de MOve) was upgraded to include bidirectional functionality – specifically to allow electric vehicles to serve as emergency power sources. Today, Tokyo operates dedicated bidirectional charging stations that can supply critical infrastructure with energy from hundreds of EVs in the event of natural disasters. Although the technology is mature (many models, like the Nissan LEAF, have supported V2G for years), full integration with the energy market is progressing gradually. Japan’s focus remains primarily on energy security and blackout resilience.
• Europe (UK and the Netherlands): Leading the Way. In Europe, the UK and the Netherlands are among the leaders in V2G development. The UK government launched a £30 million funding program in 2018 to support 20 V2G pilot projects involving around 600 vehicles. In one of these pilots, energy provider OVO Energy tested a model where private EVs discharged energy back to the grid in the evenings – participants earned up to £500 per year for their contributions. In the Netherlands, MyWheels launched Europe’s largest V2G-based car-sharing project, using 500 electric Renault ZOEs to feed energy back into the grid during peak demand. Another notable pilot is underway in Utrecht, where bidirectional chargers support Hyundai Ioniq 5 vehicles – parked EVs act as local energy storage for nearby residential areas.
• China and Other Regions: In China, the rapidly growing electric bus fleet is already participating in dozens of V2G pilot programs. Over 30 projects are active across 9 major cities, where public and commercial buses discharge energy to the grid during peak hours.
  Australia is testing home energy storage models using popular EVs like the Nissan LEAF and bidirectional chargers. Meanwhile, Canada is joining the trend by integrating city buses and logistics trucks into grid-balancing strategies.

The Global Outlook. The global direction is clear: as e-mobility becomes more widespread, so does the interest in turning EVs into distributed, mobile energy assets that support the energy transition. Estimates suggest that the V2G market, currently worth several billion dollars, could exceed $100 billion within a decade – growing at a rate of several dozen percent annually.

Benefits of V2G Technology

For Power Grid Operators:

• Better balancing of supply and demand within the power system.
• Energy discharge during peak hours, reducing grid load and the risk of overloads.
• Improved voltage stability and reduced need for costly reserve power plants.
• Potential to treat EV fleets as “virtual power plants” that respond dynamically to grid needs.

For Electric Vehicle Users:

• Lower total cost of EV ownership and the opportunity to generate additional income.
• Charging during low-cost nighttime hours and selling energy back during expensive peak times.
• Emergency backup power for homes (Vehicle-to-Home functionality).
• Increased energy security for households.

For the Renewable Energy Sector and Energy Transition:

• Easier integration of renewable sources by using EVs as distributed energy storage.
• Reduced energy waste during periods of RES overproduction.
• Greater system flexibility and capacity to connect more wind and solar farms.
• Lower CO₂ emissions through better use of green energy and reduced reliance on conventional peak power plants.

Technological, Infrastructure, and Economic Challenges of V2G

• Technical issues and battery lifespan: Frequent charging and discharging cycles can accelerate battery degradation. Smart algorithms are needed to protect batteries from excessive wear. Studies show that with proper energy management, the impact of V2G on cell longevity can be minimal.
• Infrastructure and standards: Most existing charging stations do not support bidirectional energy flow. Investments in V2G-compatible chargers and standardized communication between the vehicle, station, and grid operator are essential. Various technological approaches (CHAdeMO, CCS, ISO 15118) require harmonization.
• Profitability and business models: V2G must be financially viable for both users and operators. Aggregation platforms and new market services are needed to integrate distributed energy resources from EVs. Until the number of V2G-enabled vehicles increases, achieving economies of scale remains difficult.
• Lack of legal and tariff frameworks: In many countries, there are no clear regulations allowing energy to be fed back into the grid from vehicles or compensating users for doing so. Legal changes are needed to eliminate issues such as double grid fees and to introduce dynamic tariffs that encourage charging and discharging at optimal times.

Regulatory Aspects in Poland and Worldwide

Legal regulations play a key role in the development of V2G. In the European Union, awareness of the technology’s potential is growing, as evidenced by the AFIR regulation, which requires member states to assess the feasibility of V2G integration.

In Poland, there are currently no public charging stations supporting V2G. Only research projects have been conducted, including collaborations with the Warsaw University of Technology. In the coming years, amendments to the Electromobility and Alternative Fuels Act will be necessary, along with new regulations defining the status of bidirectional chargers, energy settlements, and tax issues.

It’s worth noting that NFOŚiGW (National Fund for Environmental Protection and Water Management) is already considering expanding support for V2G chargers in future editions of the “Mój Prąd” program. The current sixth edition includes subsidies for photovoltaics, electric and thermal energy storage, and energy management systems. Adding support for bidirectional chargers would be a natural next step – especially as prosumers increasingly seek solutions that allow them not only to store energy but also to actively participate in grid balancing.

In 2025, Poland’s National Fund for Environmental Protection and Water Management (NFOŚiGW) launched large-scale funding programs for electromobility infrastructure, with a total value of PLN 6 billion. These initiatives support fast and ultra-fast charging stations for both passenger and heavy-duty transport. Although V2G chargers are not yet included, the institution does not rule out their inclusion in future rounds, especially as regulations evolve and the technology becomes more widely available.

Compared to other European countries, Poland is just beginning this journey. In Germany and the UK, barriers such as double grid fees have already been removed, allowing electric vehicles to be treated as standard energy storage units. Japan and South Korea plan to establish full V2G standards by 2027, while the United States is working on simplifying grid connection procedures and standardizing communication protocols.

Conclusion

Vehicle-to-Grid (V2G) technology has the potential to become the missing link in the energy transition – connecting the rapidly growing world of electromobility with the evolving needs of the power grid. EVs equipped with V2G act as mobile energy storage units, and at scale, they can provide the flexibility needed to stabilize a grid increasingly powered by renewables.

The future of e-mobility is not just about zero-emission vehicles – it’s about smart, connected cars that actively participate in the energy market. If we create the right technical and legal conditions, millions of electric vehicles could collectively offer massive energy capacity and power to the grid. This would significantly reduce energy system costs and increase the ability to integrate new wind and solar farms.

E-mobility as mobile energy storage will help us better harness the potential of clean energy and make our grid more resilient, flexible, and cost-effective. This is not a distant vision – it’s a real direction that is already shaping the future of energy and transport.